The efficacy of intravenous moxaprindine on ventricular ectopic activity.

Moxaprindine, a new derivative of aprindine, has been showed to possess strong antiarrhythmic properties in the dog. It is significantly less toxic than aprindine on hematopoietic cells in culture. This drug was given intravenously (2 mg/kg given over a 30 min period), to 10 patients with severe, refractory and symptomatic ventricular arrhythmias. In 8 of them, all ventricular ectopic activity was suppressed for at least 90 min following the end of perfusion. In 7, no ventricular ectopic beats recurred before the end of the experimentation (150 min). There were two non-responders: one of them developed a torsade de pointes phenomenon under the influence of the drug. The mean drug concentration which was reached at the end of perfusion was 4.83 +/- 2.46 gamma/ml. It progressively fell to a value of 1.11 +/- 0.35 gamma/ml, 150 min later. The drug prolongs the PR interval, QRS duration and QT interval. Moxaprindine is a powerful antiarrhythmic agent which deserves further assessment in long term studies.